1. Technical Field
The present disclosure relates to a speaker, and more particularly, relates to a speaker for emitting sound according to the thermal acoustic effect.
2. Description of Related Art
A common type of speaker is a moving-coil speaker. Moving-coil loudspeakers employ a magnetic “motor” to produce movement of a diaphragm which, in turn, produces sound. A cone is typically disposed within a frame of the diaphragm, with the wide end of the cone coupled to the frame by way of flexible membrane, called a suspension or surround, which axially centers the cone within the frame, yet allows back and forth motion at audio frequencies. The narrow end of the cone is coupled to the frame by another flexible membrane, called a spider, which also helps to axially center the moving diaphragm.
The motor is made up of a voice coil, disposed behind the narrow end of the cone, and a magnetic circuit, disposed adjacent to and/or partially surrounding the voice coil. In operation, electrical audio signals from an amplifier (or other source) are applied to the voice coil, producing a varying electromagnetic field. This interacts with the magnetic field of the magnet circuit, causing the voice coil to move. Because the voice coil is coupled to the diaphragm, its movement causes the diaphragm to expand and contract, pressurizing and depressurizing surrounding air and, producing sound waves.
Moving-coil loudspeakers, however, consume considerable power can be too large for many practical applications. Although the art has made strides toward minimizing these shortcomings, there remains a need for a compact and low power consumption speaker that can be easily installed and efficiently operated.